ST72215G2 STMicroelectronics, ST72215G2 Datasheet - Page 110

• Manufacturer Part Number: ST72215G2
• Description: 8-BIT MCU WITH SINGLE VOLTAGE FLASH MEMORY,ADC, 16-BIT TIMERS, SPI, I2C INTERFACES
• Manufacturer: STMicroelectronics

Specifications of ST72215G2

• Emulation Voltage: 5.5 V

ST72104Gx, ST72215Gx, ST72216Gx, ST72254Gx
CLOCK CHARACTERISTICS (Cont’d)
13.5.4 RC Oscillators
The ST7 internal clock can be supplied with an RC
oscillator. This oscillator can be used with internal
Figure 66. Typical Application with RC oscillator
Figure 67. Typical Internal RC Oscillator
Notes:
1. Data based on characterization results.
2. Guaranteed frequency range with the specified C
Data based on design simulation.
3. Data based on characterization results done with V
4. R
5. Important: when no external C
is subject to high variation (package, application...). In this case, the RC oscillator frequency tuning has to be done by
trying out several resistor values.
110/141
f
t
R
C
Symbol
OSC
SU(OSC)
EX
EX
EXTERNAL RC
EX
fosc [MH z]
4.3
4.2
3.9
3.8
4.1
4
must have a positive temperature coefficient (ppm/°C), carbon resistors should therefore not be used.
3.2
Internal RC oscillator frequency
External RC oscillator frequency
Internal RC Oscillator Start-up Time
External RC Oscillator Start-up Time
Oscillator external resistor
Oscillator external capacitor
R
EX
C
EX
-40°C
+25° C
ST72XXX
OSC1
OSC2
V DD [V]
Parameter
EX
is applied, the capacitance to be considered is the global parasitic capacitance which
+85° C
+125°C
4)
INTERNAL RC
1)
2)
5.5
3)
3)
EX
DD
see
R
R
R
R
see
and R
EX
EX
EX
EX
nominal at 5V, not tested in production.
=47KΩ, C
=47KΩ, C
=10KΩ, C
=10KΩ, C
Figure 67
Figure 68
EX
Conditions
Voltage generator
or external components (selectable by option
byte).
Figure 68. Typical External RC Oscillator
V
ranges taking into account the device process variation.
REF
fosc [MHz]
20
15
10
5
0
EX
EX
EX
EX
=”0”pF
=100pF
=6.8pF
=470pF
0
+
-
6.8
22
3.60
Min
V
0
10
1
DD
5)
Cex [pF]
47
Typ
2.0
1.0
6.5
0.7
3.0
100
C
EX
Current copy
Rex= 10KOhm
Rex= 15KOhm
Rex= 22KOhm
Rex= 33KOhm
Rex= 39KOhm
Rex= 47KOhm
Max
discharge
5.10
470
14
47
270
f
OSC
MHz
Unit
KΩ
ms
470
pF